git-split

README

git-split, an interactive commit-splitting tool for Git

It's generally better in a code review that individual commits be focused to complete exactly one logical action. The reviewer doesn't have to maintain and switch contexts, and reviews are generally much more accurate and faster.

But, often development happens non-linearly, and even when it does manage to happen in a linear fashion, it's easy to create something monolithic before you remember to create a new commit.

git-split means to address that by allowing you to split individual commits into multiple commits interactively, with a simple file-chunk-line tree view and checkbox selection. Simply select what you want to be in the first and subsequent commits with each iteration. Once there is no difference between HEAD and your target commit, git-split exits and rebases the branch you were previously in on top of the tip of the split commits.

Something went wrong? Don't like the result? git-split also creates a backup of the old branch as git-split-backup/<branchname>[.#], appending an incrementing number if the same branch is split multiple times.

Installation

Install git-split to a location on your path. Git automatically aliases binaries prefixed with git- as a new Git command, so you can either use git split or git-split

Usage

git split [commit ref]

If a commit ref is not provided, will split the current HEAD commit.

The current branch at the time of execution will be rebased to the new commits upon successful completion (where the new tip commit matches the original target commit ref and the user has not aborted at any stage)

Navigating the UI

Quick Reference

These are also mostly listed at the top of the UI, with some unlisted shortcuts using shift:

• up/down arrow: Navigate files/chunks/lines. shift or pgup/pgdn moves up or down 15 lines.
• left/right arrow: Collapse/expand files/chunks. shift collapses or expands all.
• spacebar: Toggle the selected state of the currently highlighted file/chunk/line
• a: Select all files/chunks/lines. shift deselects all files/chunks/lines.
• q or ctrl-c: abandon splitting and return to the original state.
• c: confirm changes: currently selected files/lines/chunks will be included in a new commit. If any changes remain, you will be asked if you want to continue splitting (y reopens the UI to split again; n bundles the remaining changes in a final commit to bring the changes up to parity with the original commit)

Can't you do this with git-rebase?

The official documentation for splitting commits in Git is something like as follows:

1. Start an interactive rebase (git rebase -i/--interactive) and change the action on the commit you wish to split to e/edit
2. Do a soft reset to the commit's target branch parent (git reset HEAD^), which leaves the target commit's changes unstaged.
3. Edit the files, likely through the git add -i/--interactive or -p/--patch functionality, which sequentially iterates through chunks, choosing what to do with each chunk. If you want to edit less than a chunk, you then enter an edit mode for the chunk before continuing.

So the short answer is: yes, but as with most Git things, it's harder than it needs to be and could easily result in wasting time fixing your broken commits or branch through reflog or such, especially if you didn't create a backup branch on the old tip.